Combinations of hydroxyalkyl-n-methyl taurines and anionic surfactants as synergistic emulsifiers

ABSTRACT

EMULSIFYING AGENTS CHARACTERIZED BY UNUSUAL MILDNESS TOWARD THE SKIN ARE DESCRIBED WHICH CONSIST ESSENTIALLY OF A SYNERGISTIC COMBINATION OF A WATER SOLUBLE TAURINE SALT OF THE GENERAL FORMULA:   R1-CH(OH)-CH2-N(CH3)-CH2-CH2-SO3M   WHEREIN R1 IS SELECTED FROM THE GROUP CONSISTING OF ALKYL AND OXAALKYL RADICALS HAVING FROM 10 TO 18 CARBON ATOMS AND M IS A WATER-SOLUBILIZING CATION AND A SURFACE ACTIVE ORGANIC SULFATE OR SULFONATE DETERGENT, THE ORGANIC PORTION OF WHICH CONSISTS OF THE ATOMS C, H, OR AMIDO NITROGEN AND HAVING FROM 8 TO 20 CARBON ATOMS. THE TAURINE SALT IS PREFERBALY PRESENT IN A WEIGHT RATIO OF APPROXIMATELY 1:3 TO 3:1 WITH THE SULFATE OR SULFONATE DETERGENT INGREDIENT.

United States Patent Oifice US. Cl. 252-526 Claims ABSTRACT OF THE DISCLOSURE Emulsifying agents characterized by unusual mildness toward the skin are described which consist essentially of a synergistic combination of a water soluble taurine salt of the general formula:

wherein R is selected from the group consisting of alkyl and oxaalkyl radicals having from to 18 carbon atoms and M is a water-solubilizing cation and a surface active organic sulfate or sulfonate detergent, the organic portion of which consists of the atoms C, H, O or amido nitrogen and having from 8 to 20 carbon atoms. The taurine salt is preferbaly present in a weight ratio of approximately 1:3 to 3:1 with the sulfate or sulfonate detergent ingredient.

This application is a continuation-in-part of our copending application Ser. No. 573,192, filed Aug. 18, 1966 now abandoned.

This invention relates to a novel emulsifier, and more particularly, concerns compositions comprising a synergistic combination of hydroxyalkyl-N-methyltaurines with surface active organic sulfate and sulfonate detergents. These compositions have markedly improved characteristics which promote the formation and stabilization of oil and water emulsions which exhibit unusual mildness toward the skin,

It is well known in the art that surface active compounds in general act as emulsifying agents and are of primary importance in stabilizing oil-in-water or waterin-oil emulsification. The ability to form such emulsions is an important property for dishwashing purposes as well as for a variety of other applications.

The preparation and utility of hydroxyalkyl-N-methyltaurines as active detergent ingredients has been disclosed in the Cahn et a1. Canadian Pat. No. 701,363. However, it has been heretofore unknown that these materials exhibit unusually strong synergistic effects when taken in combination with organic sulfates and sulfonates as emulsifiers for oil and water systems. The combined materials are many times more effective as an emulsifying system than either of the individual materials alone. These combinations are also unexpectedly mild detergents, and hence especially suitable for dishwashing purposes.

The salts of the taurines employed in the present invention have the following formula:

in which R, is an alkyl or oxaalkyl having from about 10 to about 18 carbon atoms, and M is a water-solubilizing cation. In preferred compounds, R contains from 12 to 18 carbon atoms. The water-solubilizing cation used may be any of those well known in the art, such as the alkali metal ions, ammonium ions, or the substituted ammonium ions such as trimethyl-ammonium, triethanolammonium,

3,649,543 Patented Mar. 14, 1972 or morpholinium. Obviously, sodium, potassium, and ammomum are preferred for reasons of economy and availabllity. The alkyl group of the N-(Z-hydroxyalkyD-N-methyltaurines may be either straight or branched chain and may be derived from either synthetic or natural sources.

I Typical compounds include, but are not limited to, N-(2- hydroxyalkyl)-N-methyltaurines of the above formula in which the radical R is C C C 4, C16, etc. as well as taurines in which R is of the formula n 2n+1"' 2 n being from 11 to 17.

The surface active organic sulfate and sulfonate detergents which may be used in the present invention are the salts of the water-solubilizing cations mentioned above with organic sulfuric and sulfonic acids, the organic portion of which consists of the atoms C, H, O or amido nitrogen, and has from about 8 to about 20 carbon atoms. The hydrocarbon portion of the organic acid generally is characterized by at least one aliphatic or aryl-aliphatic radical containing between about 8 to 20 carbon atoms; however, the organic portion may also contain functional groups such as carboxyl, ether and the like. The aliphatic group may be saturated or unsaturated. Moreover, the aliphatic portion of the organic radical may be either a branched chain group derived from the older synthetic processes, such as polymerization of propylene, or it may be a straight chain group whereby the property of biodegradability can be obtained:

Typical classes of sulfates and sulfonates which may be used are:

(1) Alkanesulfonates of the formula RSO M (2) Alkenesulfonates of the formula RSO3-M (3) Sulfated alcohol-ethylene oxide condensates of the formula R(OC H ),,OSO M (4) Alkoxyhydroxypropanesulfonates of the formula ROOH CH(OH)CH SO M (5 Taurates of the formula 0 R-( JN(CH )CHZCH SO M (6) Sulfated fatty monoethanolamides of the formula 0 R NH-CHzCH2OSD;-M

(7) Linear alkylbenzenesulfonates of the formula wherein the phenylene group is randomly attached along the straight hydrocarbon chain.

(8) Alkyl phenoxy polyoxyethylene sulfates of the formula (9) Arnidomethanesulfonates of the formula (l) Acyl isethionates of the formula 0 R-f'l-O-CHzCHz-S O3-M (ll) N-(acyloxyethyl)sulfoacetamide of the formula R in the foregoing eleven formulas represents an aliphatic hydrocarbon radical having about 8 to about carbon atoms, but having about 8 to about 15 carbon atoms when it is attached to a phenylene group.

Some of the foregoing classes are illustrated by the following specific compounds:

sodium dodecyl sulfte triethanolammonium dodecyl sulfate sodium 3-dodecyloxy-2-hydroxypropane-l-sulfonate the sodium salt of N-acyl isethionic acid, the acyl group being derived from coconut fatty acids the sodium salt of a sulfated condensate of 3 molar proportions of ethylene oxide and 1 molar proportion of stearyl alcohol potassium dodecylbenzenesulfonate derived from phenylpolypropylene ammonium linear-alkylbenzenesulfonates having an average of 12 carbon atoms in the alkyl group sodium paraffin sulfonate To obtain the greatest synergistic effects, the N-methyltaurine salts of the present invention should be present in 'weight ratio of approximately 1:3 to 3:1 with respect to the sulfate or sulfonate detergent ingredient. It will be recognized that the essential synergistic activity obtained by the combination of the taurines of the present invention and sulfate or sulfonate detergents will be realized if these components are used in the appropriate ratios in a composition composed only of these two active ingredients, or in which the active ingredients are taken further in combination with one or more other components whereby a formulation, either liquid or solid, may be obtained for addition to an oil-in-water emulsion to be stabilized. For instance, in a typical formulation based upon the combination of a taurine as described above and a sulfate or sulfonate detergent, there may be from about 2% to about of each of the taurine and the sulfate or sulfonate detergent components, up to 15% of an amide of a fatty acid in which one or both of the hydrogens of the arnido nitrogen are replaced by lower alkyl or lower alkanol groups, and up to about of an inonganic or organic builder to enhance the emulsifying activity of the combination of the present invention. In typical compositions employing emulsifiers in combination with other components, the total of the taurine and the sulfate or sulfonate will normally be between about 10% and about 40% by weight of the composition.

Typical amides which may be mentioned include, but are not limited to lauric monoethanol amide, lauric diethanol amide and lauric isopropanol amide. In other amides the lauric group may be replaced by myristoyl, palmitoyl, stearoyl, oleoyl, gadoloyl, erucoyl, etc., or mixtures of the foregoing, such as mixtures of lauroyl and myristoyl, and mixtures derived from naturally occurring fats and oils, such as coconut oil and tallow. In addition to the amides mentioned above, the unsubstituted amides, such as lauramide or the unsubstituted amide derived from coconut oil, may be used in granular products.

The inorganic builders contemplated are those commonly used in detergent formulations. Such builders include, but are not limited to, the alkali metal tripolyphosphates, tetraphosphates, hexametaphosphates, septaphosphates and decaphosphates, such as pentasodium triphos phate. In addition certain orthophosphates and pyrophosphates such as potassium, sodium and ethanol, diethanol and triethanol pyrophosphates are useful. Other inorganic compounds include alkali metal and ammonium silicates, carbonates, chlorides, sulfates and borates, and the alltaline salts of nitrilotriacetic acid. Examples are sodium silicate, bentonite, sodium carbonate monohydrate, sodium and potassium chloride, sodium and ammonium sulfate. sodium borate and the like.

Other adjuvants which may be used without altering the essential nature of this invention include, but are not limited to, the cellulosic anti-soil redeposition aids such as methylcellulose, hydroxymethyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, carboxymethy hydroxyethyl cellulose, and hydroxypropylcellulose. Certain organic polymers such as sodium polyacrylate and polyvinyl alcohol and the like have been found useful as builders in addition to some organic esters such as ethylene glycol monostearate and methyl palmitate. Higher fatty acid amides such as palmitylethanolamide, myristylethanolamide, laurylethanolamide, oleylethanolamide, myristamide, lauramide, stearamide, lauric diethanolamide, higher fatty acid amides of monoisopropanolamine (e.g. capryl, lauroyl and myristoyl isopropanolamide) and amide type mixtures prepared from mixtures of higher fatty acids derived from various fats, oils and waxes of animals, marine or vegetable origin may also be used as organic builders. Other amides suitable for use in our invention are N,N bis(lower alkylol) higher fatty acid amides such as N ,N bis(2-hydroxyethyl) lauramide, N,N bis(Z-hydroxyethyl) myristamide, N,N, bis(Z-hydroxyethyl) coconut fatty acid amide, N,N bis(2,3-dihydroxypropyl) lauramide, N,N bis(2,3-dihydroxypropyl) myristamide, N,N bis(3-hydroxypropyl) lauramide, N,N bis(3- hydroxypropyl) capramide, N,N bis(2-hydroxypropyl) lauramide, N,N bis(Z-hydroxypropyl) myristamide, N,N bis(4-hydroxybutyl) lauramide and the like.

In the foregoing it will be obvious to those skilled in the art that of the alkali metal salts which may be used, sodium and potassium salts are the commercially most important.

In use, improved emulsification or emulsion stability is obtained by providing, in an emulsion of oil and water, for at least about 0.001% of a mixture of the taurine plus the sulfate or sulfonate detergent based on the weight of the water. For many applications, an amount of emulsifier between about 0.005% and 0.5% is particularly appro priate. However, it will be recognized that higher concentrations of emulsifier may be appropriate for systems which emulsify with gerater difficulty.

For a further understanding of the present invention, reference may be had to the following examples. In the examples, the N-(2-hydroxyalkyl)-N-methyltaurines were obtained by reacting a l,2-epoxyalkane with sodium N- methyltaurine in equimolar proportions. The 1,2-epoxyalkane was in turn obtained by epoxidizing a C12-C16 cut from a Ziegler type alpha-olefin.

The N-(2-hydroxyoxaalkyl)-N-methyltaurines were obtained by reacting a C -C primary alcohol with epichlorohydrin, and in turn epoxidizing the resultant intermediate to obtain a C C oxaalkyl epoxide. This last mentioned compound is then reacted in an analogous manner with N-methyltaurine.

To evaluate the emulsifying properties conveniently, a special test was devised as follows:

480 cc. of tap water at 116 F. were added to a 600 cc. beaker. 0.1 cc. of a 35% detergent solution or the equivalent was added to the water, followed by the addition of 20 cc. of Wesson oil. The mixture was then stirred for 1 minute at 435 r.p.m. with a Bodine motor (type NSE-llR) using a metal stirrer with a 5 x 1.6 cm. blade. The stirrer blade was placed so that 8 cm. of the shaft was immersed below the surface of the liquid. The emulsion was then allowed to stand at room temperature and the amount of oil separation was noted as a function of time.

Employing the foregoing test procedure, the emulsifying properties of a number of detergent solutions were measured.

EXAMPLE 1 The emulsifying property of a C -C N-(Z-hydroxyalkyl)-N-methyltaurine (HAMT) sodium lauryl sulfate (Na L.S.) and mixtures of the two were measured. The

results are summarized in the following table: 7 5

TABLE 1 Percent oil separated after Test compositions 20 min. 1 hr. 2 hrs. 3 hrs. 4 hrs. 5 hrs. 6 hrs. 7 hrs. 8 hrs.

0.028% G -C HAMT 2-5 5 70 80 90 100 0.028% Na. L.S 100.- 0.0Ig77ig1rCu HAMT plus 0.021% Trace--. Trace. Trace- Trace Trace Trace Trace 2-5 2-5 a 0.014% CHCII HAMT plus 0.014% ...do do.... do 2 2-5 2-5 2-5 5 5 a 0.021% Cir-Cm HAMT plus 0.007% do 2 2 5 5 5 5 5 5 Na L.S.

EXAMPLE 2 20 The test set forth above was repeated, employing a variety of other mixtures of N (Z-hydroxyalkyD-N- methyl-taurine and a sulfate or suifouate detergent. The results are set forth below.

TABLE 2 Percent oil separated after- Test compositions 30 min. 1 hr. 2 hrs. 4 hrs. 10 hrs. 28 hrs.

0.056% 015-0 HAMT 30 50 60 90 100 0.056% Na dodecyl sulfate 0 0 1 20 80 95 0.014% 015-0 5 HAMT, 0.042% N21 dodecyl sulfate 0 0 0 5 40 0.028% 015-0 HAMT, 0.028% Na dodecyl sulfate 0 0 0 0 1 0.042% -C1c HAMT, 0.014% Na.

dodecyl sulfate 0 0 1 10 30 0.056% Na hexadecene sulfonate 0 0 0 1 5 5 0.014% C r-C19 HAMT, 42% Na hexadecene sultonate 0 0 0 0 10 20 0.028% Orr-Cm HAMT, 0.028% Na hexadecene sulfouate 0 0 5 10 20 40 0.042% 015-016 HAMT, 0.014% Na hexadecene sulionate V 0 0 0 70 85 0.056% Na Alfol 1412 3 E0 Sulfate 1 5 15 35 75 95 0.014% C15-C1u HAMT, 0.042% Na Alfol 1412 3 E0 sulfate 0 0 0 2 5 0.028% 015-015 HAMT, 0.028% NS Alfol 1412 3 E0 sulfate 0 1 1 2 5 5 0.042% 01 -01. HAMT, 0.014% Na A1101 1412 3 E0 sulfate 10 60 80 90 100 3 hrs 10 hrs 24 hrs.

0.056% G g-Cm HAM'I 60 80 100 0.056% Na Cir-C alkanesultonate 5 25 40 50 0 014% Cir-Cm HAMT, 0.042% Na CH-C alkanesulionate 0 0 1 2 30 30 0.028% C15C10 HAMT, 0 028% Ne C14-C alkanesulfonate 0 0 0 1 1 3 0.042% C15'C10 HAMT, 0.014% Na Cir-C1 alkanesulfonate 0 0 5 10 TABLE 3 Percent oil separated alter- Test compositions 30 min. 1 hr. 2 hrs. 3 hrs. 20 hrs. 24 hrs.

0.056% G -C19 HAMT 15 40 60 100 0.056% Na dodecauesultonate 20 40 G0 70 100 0.014% 0 -010 *HAMT, 0.042% Na dodecauesuliona'te 0 0 0 0 2 3 0.028% Cir-Cm 'HAMI, 0.028% Na dodecanesulionate 0 0 0 5 10 0.042% Crs-CmHAMT, 0.014% Na dodecanesulfouate 0 0 5 10 75 0.056% Na hexadecauesulfonate 20 20 30 40 60 60 0.014% Cir-Cm H MT, 0.042% Na hexadecanesulfonate 0 0 0 2 100 0.028% C15Ci0 HAM'I, 0.028% Na hexadecanesultonate 0 0 30 60 100 ......r 0.042% Cit-Cm HAMT, 0.014% Na hexadecanesulfonate 0 0 5 70 90 0.056% Na 3-d0decyIoxy-2-hydroxypropaue-l-sulfonate 0 0 0 0 0 0 0.014% C r-C19 'HAMT, 0.042% Na 3-dodeeyloxy-2-hydroxypropaue-1-su1- fonate 0 0 0 1 1 1 0.028% Cir-C10 HAMT, 0.028% Na 3-50decyloxyfl-hydroxypropaue-l-sulfonate 0 0 0 5 5 5 0.042% Cur-C15 HAMT, 0.014% Na 3dodecyloxy-2-hydroxypropane-1-sulionate 0 0 1 50 50 TABLE 7C0ntlnue(l Pecent oil separation after- Test compositions 5 min. 30 min. 1 hr. 2 hrs. 7 hrs. 24 hrs.

0.014% Q -C OxaHAMT, 0.042%

Na Alfol 1412 3E0 sulfate 2 0 0 0 1 7 0.028% C -C OxaHAMT, 0.028%

Na Alfol 1412 3E0 sulfate 2 0 0 0 0 0 1 0.042% (lg-CuOxaHAMT, 0.014%

Na A1101 1412 3E0 sulfate 2 0 0 0 5 50 0.056% Na Chi-C1 alkanesulfate 50 50 80 80 0.014% C12-C1sOXaI-IAMT, 0.042%

Na 014-01 alkanesulfate 0 0 0 0 1 5 0.028% CWCHOxaHAMT, 28%

N a' (Du-C1 alkanesulfate. 0 0 20 0.042% C C OxaHAMT, 14%

Na Chi-C1 alkanesulfonate 0 0 0 1 5 10 1 Prepared by sulfonating l-hexadecene. 2 Aliol 1412 is a mixture of primary aliphatic alcohols about $6, of which have 14 carbon atoms and about $4 of which have 12 carbon atoms. "3EO signifies that on the average, 3 oxyethylenc units (or 3 moles of ethylene oxide) are combined with each mole of alcohol.

TAB LE 8 Test compositions Percent oil separation after- 0.056% Cm'CmOxaHAMT 0.056% Na linear alkylbenzenesulionate 0.014% C 2-C OxaHAMT, 0.042%

Na linear alkylbenzenesulfonate. 0.028% C12-C130x2tHAMT, 0.28% Na linear alkylbenzenesnlfonate 0.042% Cg-CnOxaHAMT, 0.014%

Na linear alkylb enzenesulfonatm. 0.05% Na salt of the suliated monoethanolamide of lauric acid 0.014% C12-C13OXEHAMT, 0.014%

Na salt of the sulfated monoethanolamide oi lauric acid 0.028% C -CmOxaHAMT, 0.028%

Na salt of the sulfa-ted mcncethanolamide of lauric acid 0.042% C12-C1aOxaHAMT, 0.014%

N a'salt of the suliated monoethanolamide of laurlc acid 0.056% Na salt of the sulfated monoethanolamide of palmitic acid 0.014% C -O OxaHAMT, 0.042%

Na salt of the sulfated monoethanolamide o1 palmitic acid 0.028% Cn-CmOxaHAMT, 0.028%

Na salt of the snliated monoethanolamide of palmitic acid 0.042% cirCuoxaHAMT, 0.014%

Na salt of the suliated monoethanolamide of palmitic acid Trace 5 30 1 As used herein, the term OxaHAMT refers to the compound TAB LE 9 Percent oil separation after- Test compositions 5 min.

30 min. 1 hr. 2 hrs. 8 hrs. 24 hrs.

O OOOQOO TABLE 10 Percent oil separation after- Test compositions 5 min. 30 min. 1 hr. 2 hrs. 8 hrs. 24 hrs.

.056% CH-CHOxaHAMT 0 0 0 10 50 70 0.056% Na 3-dodecyl-2-hydroxypropane-l-suli'onate u 0 0 0 0 0.014% Cn-CraOxaHAMT, 0.042%

N a 3-dodecyl-2-hydroxypropane-1- sulfonate 0 0 t) 0 3 0 0.028% Cn-CraHAMT, 0.028% Na 3- dodecyl-2-hydroxypropane-1- sulfonate 0 0 0 0 0 0 0.042% Cn-Cu0xaHAMT 0 0 0 0 1 5 0.056% N a N -(tallow)acyl-N-methyl taurate 0 J 0 0 0 0 0.014% C1z-C13OX8HAMT,0.042% Na N-(tnllow)acy1-N-methyl taurate 0 0 0 0 0 Trace 0.028% G n-CuOxaHAMT, 0.028% Na N -tta11ow)acyl-N -methyl taurate 1 0 0 0 0 2 0.056% Na 3-alkoxy-2-hydroxypropane-l-sulfonate 15 50 l00 0%475 cl lg-ouglglfilrkMT, 0.042%1 a -a oxyo propanesulfonate 1--.? l 0 0 0 0 0 0.028% C12-C1aOxaHAMT, 0.028%

Na 3-alkoxy-2-hydroxypropane-lsulfonate 0 0 0 0 0 0 0.042% Cu-CnOxaHAMT, 0.014%

Na 3-alkoxy-2-hydroxypropane-1- sulfonate 0 0 0 0 0 0 TAB LE 11 Percent oil separation after- Test compositions 5 min. 30 min. 1hr. 2 hrs. 7 hrs. 24 hrs.

0.056% C -CnOxaHAMT 0 0 0 10 40 10 0.056% KC" phenoxy (polyethoxyh sulfate (n=6) 0 0 0 Trace 2 5 0.014% Crz-CnOxaHAMT, 0.042% K012 phenoxy (polyethoxyh. sulfate ("=6 0 0 0 Trace Trace 10 002.8% c -ouoxzin aiig, 0.028%

012 henox o e ex :1 sulfate =6 Yu 3 "Y 0 1) 0 0 1 10 0.042% Cu-CnOxaHAMT, 0.014% K011 phenoxy (polyethoxyh 0 gulatleI (I1I1=6) i..fi. l. 0 0 Trace 5 .30 B5 56 o 4 nony p enoxy 110 yoxyethylene),I sulfate (n=4) 0 0 0 0 0 0 0.014% C12-C1aOXaHAMT, 0.042%

NH; nonyl phenoxy (polyoxyethyleneh sulfate (n=4) 0 0 0 0 0 0 0.028% Cm-CraOXBHAMT, 0.028%

NH nonyl phenoxy (polymryethylene).l sulfate (n=4) 0 0 0 0 0 Trace 0.042% Cu-CuOxaHAM'I, 0.014%

NH; nonyl phenoxy (poly- 0 oxyethyllierligh sulfate tng txalnluu 1 11) 0 0 Trace Trace .056 N 4 coco ac -me tauz ate -EUHZUY 1-.-- 0 0 Trace 1 10 20 0.014% Cn-CuOxaHAMT, 0.042%

Na N-(eoco)acyl-N-methyl taurate 0 0 0 1 5 15 0.028% Cm-CmOxuHAMT, 0.028%

Na -(coco)acyl-N-methyl taurate 0 0 0 0 5 0.042% Cu-CnOxaHAMT, 0.014%

Na N -(coco)acyl-N-methyl taurate. 0 0 0 1 5 In most of the foregoing cases, as Wlll be noted, either EXAMPLE 3 the N-(Z-hydroxyalkyl)-N-methyltaurinc or the other detergent used alone in a concentration of 0.056% was markedly less effective as an emulsifying agent, and in all cases the combination of detergents was more efiFective than would be predicted based on a linear addition of the individual components.

The test outlined in Example 1 was repeated again, this time using active ingredients in a concentration onefifth of that employed in Example 1. In this illustration,

the synergism between a C C HAMT and a potassium C C alcohol-3 ethylene oxide sulfate is illustrated.

The results obtained are set forth in Table 12.

As already suggested, because of its superior ability as an emulsifier, the combination of an N-( 2-hydroxya1kyl)- N-methyltaurine and a second detergent is of particular value in dishwashing formulations. The dishwashing detergent may be in either liquid or powder form; however, as is well known, the liquid form of detergent is by far the preferred form for consumer acceptance. In liquid form the formulation will consist essentially of from (A) 5% to 21% of a surface active organic compound which is a member of the group consisting of salts of water solubilizing cations with the organic sulfuric and sulfonic acids described above, (B) from 9% to 13% of the salt of C12-C20 N-(2-hydroxyalkyl)-N-methyltaurine with a water solubilizing cation, the ratio of (A) to (B) being between 3:1 and 1:3, and (C) sufficient water to yield a liquid.

A typical formulation embodying the present invention adapted to be used as a liquid dishwashing detergent may have the following composition:

Percent Alkali metal or ammonium alcohol-3.1 ethylene (Londensates containing from 1 to 10 moles of ethylene oxide per mole of alcohol may be used. The alcohol contemplated is the hydroxy derivative of an acyclic, aliphatic hydrocarbon which contains from about 12 to about 14 carbon atoms.

The N (2 hydroxyalkyl)-N-rnethyltaurines may be pure components; however mixtures in the range of '01; and Cm alkyl groups will be of greater practical availability. The cation may be an alkali metal orammonium. OxaHAMT may be substituted for HAMT in the sameamount.

Salts are frequently desired to increase the viscosity of the liquid for purposes of consumer acceptance. Sodium and potassium chlorides, sulfates, monethanol ammonium sulfates, and bicarbonates are particularly useful in this respect.

With respect to the solubilizers mentioned in the fore going formulation, all materials commonly classified as solubilizers would be suitable. Included are the various alcohols, preferably the saturated, aliphatic type, which also provide freeze-thaw stability to the detergent. These alcohols may be monoor polyhydric and may contain inert solubilizing groups such as ether linkages. Examples of monohydric alcohols are methyl, ethyl, n-propyl, isopropyl and n butyl alcohol or mixtures thereof. Higher monohydric alcohols are not preferred since they have a comparatively undesirable odor and generally exhibit less solubility in water. Among the many suitable polyhydric alcohols are ethylene, propylene, and hexylene glycol, glycerol or mixtures thereof. Suitable alcohols possessing ether linkages are the monoethyl ethers of ethylene and diethylene glycol, the monobutyl and monomethyl ethers of di ethylene glycol, dioxane and the like.

In lieu of the foregoing alcohols, the low molecular weight aryl and alkylaryl sulfonates may also be used as solubilizers, such as the alkali metal alkylarenesulfonates derived from benzene, naphthalene, diphenyl and diphenylmethane. In addition, the soluble alkali metal and ammonium sulfonates of benzene, toluene, cumene and xylene may also be used. Examples are the ethanol, diethanol and triethanol ammonium benzene sulfonates and potassium and sodium toluene sulfonate.

EXAMPLE 4 The detergent actives mentioned in the above formula were tested for dishwashing performance by comparison against a standard commercial liquid dishwashing detergent. Batches of plates soiled under standard conditions were washed in dishwashing solutions prepared by adding 6 grams to 6 quarts of water at 120 F. of either 14 the standard dishwashing detergent or a test formulation. The number of plates washed before disappearance of the suds was observed, with the following results:

A comparison was made between test detergent (A) containing 12% of a C C N (2 hydroxyalkyl)-N- methyltaurine and 15% of lauryl alcohol sulfate, test detergent (B) containing 27% of lauryl alcohol sulfate, test detergent (C) containing 27% of N-(2-hydroxyalkyl)-N- methyltaurine, and test detergent (D) which was a commercial liquid dishwashing detergent. Test detergent (A) washed 41 plates, test detergent (B) washed 9 plates, test detergent (C) washed 33 plates, and the commercial dishwashing detergent (D) washed 38 plates. These data clearly show a substantial improvement accruing from the use of a mixture of N-(Z-hydroxyalkyl)-N-methyltaurine and a sulfate or sulfonate in dishwashing tests. In all of the test detergents, the sodium salts were used.

EXAMPLE 5 An illustrative commercial dishwashing formulation employing the present invention is as follows:

Water, balance to make A Cite-14 straight chain alcohol sulfate. The sulfonated condensate of Alfol 1412 with 3 moles of ethylene oxide.

EXAMPLE 6 The synergistic properties of the combination of the present invention is further illustrated by tests summarized in the following table.

Commercial Formulation tested dishwashing A B C D liquid NH4 Alfol 1412.3.1 E.O. sulfate 14.1 14. l 14. 1 14. 1

AMT 5. 7

Ethyl alcohol 13. Water and misc- 66.

Number of plates washed 43 1 The suliated condensate of a 012-0 4 linear alcohol with 3.1 moles of ethylene oxide.

. The foregoing shows that excellent liquid detergents can be formed by combining HAMT with a sulfate or sulfonate detergent.

The mildness of detergents towards hands is of particular commercial importance in the manufacture and sale' of dishwashing products. We have found that the combination of sulfate or sulfonated detergents with methyltaurine salts according to the proportions of the present invention results in a composition of unexpected mildness. In three epilated guinea pig (E.G.P.) tests, the results of which are provided in Table 13, the mildness of several sodium Alfol sulfate (C -C straight chain alcohol sulfate) solutions was determined by applying specified amounts of the active material to the exposed skin of the animals being tested. Two such applications of the active material were made to ten separate portions of skin and the treated portions were observed on two occasions, twenty-four hours after each application. The average erythema reading in the tests of Table 13 is based solely upon the observations after the second application. The number (index of irritation) in the Average Erythema Reading column indicates the extent of the red- .ness which resulted and is based upon the following scoring system:

alkenesulfonates of the formula RSO M sulfated alcohol-ethylene oxide condensates of the formula R( OC H OSO;,M

TABLE 13.--MILDNESS EVALUATION BY E.P.G. TESTS Total Average active Amount Erythema erythema Concenmaterial Amount N a Alfol readings reading tratlon applied, HAMT, sulfate, on second on second Actlve material percent pH percent percent percent application application Test 1:

HAMT 20 10.4 4.0 4.0 288g Sodium Alf011412 sulfate :20 9.9 4.0 l) 4,0 g g g g g 1 HAMT plus sodium 1111011412 sulfate (75 25).. :0 11.3 4. o 11.0 1.0 l 3 g i g HAMT plus sodium Ali'ol 1412 sulfate (50 50).. to 10.4 4. o o :2. 0 g f i i g 6 Test 2:

Sodium 2111011412 sulfate .1 9. 2 1. o o 1, 0 l f g g g Sodium Alfol1412 sulfate plus HAMT 25 to a s 4. o 1.0 a. o f g 1 i f 7 HAMT plus sodium Alfol 1412 sulfate (75/25).. :0 1o. 4 4. o a. o 1. o 1 l g 3 g Sodium A1101 1412 sulfate as 4. o o 4. 0 i g g g g Test 3:

Sodium Aliol 1412 sulfate 1 us 2 o 2 l g g i HAMT plus sodium Alfol1412 sulfate 75 20 s. s s s '2 i g i f The results of the E.P.G. testing given in Table 13 conin which x is 1-10, alkoxyhydroxypropanesulfonates firm the following statements: of the formula (1) From Test 1, when 4% HAMT comprises the only active ingredient, the index of irritation was 0.3 (mild), R o CH2 CH(OH) CRT-S03 M while a similar 4% Alfol sulfate formulation exhibited taurates of the formula in two separate tests indices of (moderate irritant) 2.1 Q

and 2.5.

(2) From Tests 2 and 3, a 1% Alfol sulfate formulation is an irritant (index 1.3), but when the percentage is increased to 2%, Alfol sulfate as the sole active ingredient becomes a moderate irritant (index 2.1).

(3) From Tests 1 and 3, when 2% HAMT is added to 2% Alfol sulfate to form a mixed composition of active material, the 2% Alfol sulfate index of irritation dropped from 2.1 (moderate irritant) as exhibited in Test 3, to an index of 0.6 (mild) as indicated in Test 1.

It may be seen from the results of all three E.P.G. tests recorded in Table 13 that when HAMT comprises at least one-half of a HAMT-Sodium Alfol Sulfate mixture, a mild formulation results.

in the present invention, it has been found that detergency is not significantly influenced by pH. However, where a liquid detergent formulation is desired, the pH level should be above 8 in the detergent concentrate. Below a pH of about 8, the HAMT compounds have limited solubility.

It will be understood that the foregoing examples are for illustrative purposes only, and that the present invention is not limited thereto. Many modifications thereof will be apparent to those skilled in the art.

We claim:

1. A composition having improved properties for promoting stabilization of oil and water emulsions consisting essentially of (a) a taurine selected from the group of compounds having the formula wherein R is an alkyl radical having 12 to 18 carbon atoms or an oxaalkyl radical having the formula C H -O--CH n being 11 to 17, and M is a Water solubilizing cation; and

(b) a salt of a water-solubilizing cation with a surface active organic detergent selected from the group consisting of sodium dodecyl sulfate, alkane-sulfohates of the formula R-%N(CH3)-CH2-OHzs03'-M sulfated fatty monoethanolamides of the formula 0 l RdNH-oHOH2-0s0sM linear alkylbenzenesulfonates of the formula wherein the phenylene group is randomly attached along the straight hydrocarbon chain, alkyl phenoxy polyethylene sulfates of the formula R1 (0 C3114) O-S 03M in which x is L10, wherein, in the foregoing formulas, R is an aliphatic hydrocarbon radical having from about 8 to about 20 carbon atoms and, when attached to a phenylene group, R is an allphatic hydrocarbon radical having about 8 to about 15 carbon atoms, and M is a water-solubilizing cation,

said taurine and said detergent being present in a weight ratio between about 3:1 and 1:3.

2. A composition according to claim 1 consisting esentially of:

(a) from about 2% to about 35% of said surface active organic detergent;

(b) from about 2% to about 35% of said taurine; and

(c) up to about 55% of a detergent builder.

3. A composition according to claim 1 consisting essentially of:

(a) from about 2% to about 35% of said surface active organic detergent;

(b) from about 2% to about 35% of said taurine;

R CH(OH)CH -N(CH )CH CH SO M wherein R is an alkyl group having from 12 to '18 carbon atoms or an oxaalkyl radical having the forn being 11 to 17, and M is a water-solubilizing cation; (b) from about 5% to about 21% of a salt of a water-solubilizing cation with an organic surface active organic detergent selected from the group consisting of sodium dodecyl sulfate, alkanesulfonates of the formula RSO M alkenesnlfonates of the formula R-SO -M sulfated alcohol-ethylene oxide condensates of the in which x is 1-10, alkoxyhydroxypropanesulfonates of the formula R0-CH CH(OH)-CH SO -M taurates of the formula 0 R-ii-N(oHa 0H2-orr2som sulfated fatty monoethanolamides of the formula 0 R -NHCHzcHz0-S03M and linear alkylbenzene sulfonates of the formula wherein the phenylene group is randomly attached along the straight hydrocarbon chain, alkyl phenoxy polyethylene sulfates of the formula in which X is 1-10, wherein, in the foregoing formulas, R is an aliphatic hydrocarbon radical having about 8 to about 20 carbon atoms and, when attached to a phetylene group, R is an aliphatic hydrocarbon radical having about 8 to 15 carbon atoms and M is a water-solubilizing cation; and

(c) suflicient water to yield a liquid concentrate having a pH of at least about 8,

said taurine and said detergent being present in a weight ratio between about 3:1 and 1:3.

5. A liquid detergent concentrate according to claim 4 consisting essentially of:

(a) from 3% to 6% of an alkyl sulfate having from 12 to 14 carbon atoms in the alkyl group with a cation selected from the group consisting of the alkali metals and ammonium;

(b) from 8% to 15% ofthe salt of the sulfate of the condensate of an alcohol of an acyclic aliphatic hydrocarbon with from 1 to 10 moles of ethylene oxide, there being from 1 2 to 14 carbon atoms in the hydrocarbon group, with a cation selected from the group consisting of the alkali metals and ammonium;

(c) from 9% to 13% of said taurine, wherein said taurine has from 12 to 14 carbon atoms in R and M is selected from the group consisting of the alkali metals and ammonium,

(d) from 2% to 15% of a solubilizing agent selected from the group consisting of lower monohydric alkanols, lower alkylene and polyalkylene glycols, lower alkyl ethers of lower alkylene glycols, gycerol and dioxane and low molecular Weight alkali metal and ammonium aryl and lower alkylaryl sulfonates; and

(e) sufficient water to yield a liquid concentrate.

References Cited UNITED STATES PATENTS 3,060,124 10/1962 Ginn 252138 X 3,149,078 9/ 1964 Zmoda 252138 X 3,332,876 7/1967 Walker 252152 3,474,038 10/1969 Sepulveda et al. 252--137 3,400,148 9/1968 Quimby 252137 X FOREIGN PATENTS 701,363 1/1965 Canada 252153 LEON D. ROSDOL, Primary Examiner D. L. ALBRECHT, Assistant Examiner U.S. Cl. X.R.

252Dig 14, 153, 171, 353, 355, 357, 531, 535, 54-5, 550, 554; 260-513 N EINE'HED STATES PATENT @FFKCE cermemr a rem Patent No. 3 u 4 Dated August a 1972 Inventofls) Arno cahll t a1.

It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

i 001 1 line 28, change "preferbaly" to preferably Col. 3 line 15, change "sulfte" to sulfate Col. i line 7,- change "adjuvants" to adjuvents Col. 1 line 2H, change "animals" to animal Col. l line H7, change Y'gerater" to greater Col. 5 line 10, change "Na L.S" to Na L. S.

Col. 9, line 19, change "S O Na" to SO Na C01. 11 line 3 first 0 is not on line.

n n C01. 12 line 75, change C --C to C -C H H C01. 13 line 13, change of C to of a C 111 H l C C .q-q Col. 1 line 31, change A C l to A 12 1 Signed and sealed this 23rd day of January 1973 (sEALy' Attest:

EDWARD M.PLETCHER,JR. ROBERT GOTTSCHALK Attestlng Officer Commissioner of Patents Patent No. 3 6Ll9 5 L3 Dated A g st 1972 lnventofls) Arno Cahn et a1.

It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

{- Col 1 line 28, change "preferbaly" to preferably qg Col. 3 line l5, change "sulfte" to sulfate Col. U line 7, change "adjuvants" to adjuvents Col. 1 line 2 L, change "animals" to animal Col. l, line 17, change "gerater" to greater Col. 5 line 10, change Na L.S" to Na L. S.

Col. 9, line U9, change "S O Na" to SO Na C01. 11 line 3 first 0 is not on line.

n u C01. 12 line 75, change C 43 to C --C H H C01. 13 line 13, change of 0 to of a C1 1 ...c Col. 1 1 line 31, change A C 1 to A C 1 Signed and sealed this 23rd day of January 1973.

(sEALy' Attes't:

EDWARD MELETCHERJR. ROBERT GOTTSCHALK Attestlng Officer Commissioner of Patents 

